Hey ceph-users, we've been using the default "snappy" to have Ceph compress data on certain pools - namely backups / copies of volumes of a VM environment. So it's write once, and no random access. I am now wondering if switching to another algo (there is snappy, zlib, lz4, or zstd) would improve the compression ratio (significantly)? * Does anybody have any real world data on snappy vs. $anyother? Using zstd is tempting as it's used in various other applications (btrfs, MongoDB, ...) for inline-compression with great success. For Ceph though there is a warning ([1]), about it being not recommended in the docs still. But I am wondering if this still stands with e.g. [2] merged. And there was [3] trying to improve the performance, this this reads as it only lead to a dead-end and no code changes? In any case does anybody have any numbers to help with the decision on the compression algo? Regards Christian [1] https://docs.ceph.com/en/latest/rados/configuration/bluestore-config-ref/#co... [2] https://github.com/ceph/ceph/pull/33790 [3] https://github.com/facebook/zstd/issues/910